Procedure for operating a transmission device, particularly a 9-speed-transmission

Abstract

A method for operating a 9-speed transmission which changes operating states by actuating shift elements. At least one of the shift elements is a form-locking shift element, which disengages to implement a defined transmission operating state during which the power flow, between transmission input and output shafts, is present or interrupted. A sensor is associated with the locking shift element. An operating state of the locking shift element can be determined by the sensor. Upon a request to disengage the locking shift element, a disengagement control signal is generated and the locking shift element is actuated in the disengagement direction, depending on the disengagement control signal. The transmission is shifted to a safe operating state, in which at least the transmission output shaft can rotate, when an engaged operating state of the locking shift element is determined by the sensor even though a disengagement control signal was generated.

The invention claimed is: 
     
       1. A method of operating a transmission device ( 1 ) comprising the transmission device transferred to various operating states by actuating shift elements (A to F), at least one of the shift elements (A, F) is a form-locking shift element which is transferred from an engaged operating state to a disengaged operating state in order to implement a defined operating state of the transmission device ( 1 ) during which a power flow between a transmission input shaft ( 2 ) and a transmission output shaft ( 3 ) is either present or is interrupted, a sensor device ( 22 ) is associated with the form-locking shift element (A, F), an operating state of the form-locking shift element (A, F) is determinable by the sensor device and, if there is a request to disengage the form-locking shift element (A, F), a disengagement control signal (IF) is generated and the form-locking shift element (A, F) is actuated in a direction of disengagement depending on the disengagement control signal, the method comprising the step of:
 transferring the transmission device ( 1 ) to a safe operating state, when an engaged operating state of the form-locking shift element (A,F) is determined by the sensor device ( 22 ) even though the disengagement control signal (IF) was generated, the transmission device in the safe operating state interrupts a flow of power from the transmission input shaft to the transmission output shaft; and 
 associating the sensor device ( 22 ) with at least two form-locking shift elements (A, F) that can be subjected to actuating pressure, the transmission device ( 1 ) is transferred to the safe operating state when the form-locking shift elements (A, F) are subjected to the actuating pressure in order to implement a requested operating state change. 
 
     
     
       2. The method according to  claim 1 , further comprising the step of starting a timer (Timer) when the disengagement control signal (IF) is generated, and transferring the transmission device ( 1 ) to the safe operating state when the timer (Timer) reaches a predefined value (TimerS) and the engaged operating state of the form-locking shift element (A, F) is determined by the sensor device ( 22 ). 
     
     
       3. The method according to  claim 1 , further comprising the step of determining, via the sensor device ( 22 ), an operating state change of the form-locking shift element (A, F) proceeding from the engaged operating state toward the disengaged operating state, when a displacement that is equivalent to a requested disengagement procedure of the form-locking shift element (A, F) is determined by the sensor device in a region of a shift-element half, which is movable relative to a further shift-element half of the form-locking shift element. 
     
     
       4. The method according to  claim 1 , further comprising the step of determining, via the sensor device ( 22 ), an operating state change of the form-locking shift element (A, F) proceeding from the engaged operating state toward the disengaged operating state when, during a requested disengagement procedure of the form-locking shift element (A, F), a shift-element half to be moved relative to a further shift-element half of the form-locking shift element (A, F) is in a position equivalent to the disengaged operating state. 
     
     
       5. The method according to  claim 1 , further comprising the step of determining, via the sensor device ( 22 ), an operating state change of the form-locking shift element (A, F) proceeding from the engaged operating state toward the disengaged state when an actuating pressure of the form-locking shift element (A, F) is transitioned from a pressure level equivalent to the engaged operating state of the form-locking shift element (A, F) to a pressure level at which the form-locking shift element (A, F) is transferred to the disengaged operating state, the actuating pressure is then at a pressure level that is equivalent to the disengaged operating state. 
     
     
       6. The method according to  claim 1 , further comprising the step of defining the safe operating state of the transmission device ( 1 ) as a neutral operating state, in which the power flow between the transmission input shaft ( 2 ) and the transmission output shaft ( 3 ) is interrupted. 
     
     
       7. The method according to  claim 1 , further comprising the step of defining the safe operating state as the operating state of the transmission device ( 1 ) before the request to engage the form-locking shift element (A, F). 
     
     
       8. The method according to  claim 1 , further comprising the step of defining the safe operating state as an operating state of the transmission device ( 1 ) into which the transmission device ( 1 ) transitions when an electrical supply to the transmission device ( 1 ) fails. 
     
     
       9. The method according to  claim 1 , further comprising the step of starting a further timer, if the transmission device ( 1 ) is in a safe operating state in which all of the shift elements (A to F) are disengaged, and, once a defined time value is reached, generating a request to establish the power flow in the region of the transmission device ( 1 ) depending on the operating state. 
     
     
       10. The method according to  claim 9 , further comprising the step of finally transitioning the transmission device into the safe operating state if repeated requests to establish the power flow in the region of the transmission device ( 1 ) were unsuccessful. 
     
     
       11. A method of operating a transmission device ( 1 ) which can be transferred to various operating states by actuating shift elements (A to F), at least one of the shift elements (A, F) is a form-locking shift element which is transferred from an engaged operating state to a disengaged operating state in order to implement a defined operating state of the transmission device ( 1 ) during which a power flow between a transmission input shaft ( 2 ) and a transmission output shaft ( 3 ) is either present or is interrupted, a sensor device ( 22 ) is associated with the form-locking shift element (A, F), an operating state of the form-locking shift element (A, F) is determinable by the sensor device and, if there is a request to disengage the form-locking shift element (A, F), a disengagement control signal (IF) is generated and the form-locking shift element (A, F) is actuated in a direction of disengagement depending on the disengagement control signal, the method comprising the step of:
 transferring the transmission device ( 1 ) to a safe operating state, in which the flow of power from the transmission input shaft to the transmission output shaft is interrupted, when an engaged operating state of the form-locking shift element (A, F) is determined by the sensor device ( 22 ) even though the disengagement control signal (IF) was generated; and 
 transferring the transmission device ( 1 ) to the safe operating state when an actuating pressure that changes the operating state of the form-locking shift element is determined by the sensor device ( 22 ) even though the disengagement control signal (IF) was not generated. 
 
     
     
       12. A method for operating a 9-speed transmission device comprising the transmission device is shiftable to various operating states by actuating shift elements, at least one of the shift elements is a form-locking shift element, the method comprising the steps of:
 implementing a shift in the transmission device from a current operating state of the transmission device, in which the form-locking shifting element is engaged, to a defined operating state of the transmission device in which the form-locking shifting element is disengaged and during which a flow of power between a transmission input shaft and a transmission output shaft is either present or is interrupted; 
 associating a sensor device with the form-locking shift element, and monitoring, with the sensor device, a pressure level of an actuating pressure which is applied to the form-locking shifting element for changing the operating state of the form-locking shift element; 
 generating a disengagement control signal and actuating the form-locking shift element in a direction of disengagement based on the disengagement control signal; and 
 shifting the transmission device to a safe operating state, in which at least the transmission output shaft is rotatable independent of the transmission input shaft, when the sensor device detects that the pressure level of the actuating pressure corresponds to the pressure level at which the form-locking shift element is in the engaged operating state even though the disengagement control signal was generated.